Where do all the Santa letters go?

Between 1954 and 2009, any letter addressed generically to "Santa Claus, North Pole" was forwarded by the US Postal Service to the Alaskan North Pole Santa Letters town of the same name, where it was answered by volunteers. The US Postal Service made a decision to end the program in 2009 on privacy grounds, but it was reinstated North Pole Santa Letters shortly thereafter.